Glossary
Every term used in the lessons and on frequency, in plain English. Terms in the lessons are underlined — click one to read its definition without losing your place.
- Aerodrome controlAirfield
- The tower: control of the runway, the taxiways and the visual circuit.
- Aerodrome Traffic ZoneAirspace
- A protected zone around an airfield, typically 2 nm radius and up to 2000 ft above the aerodrome.Not the same as a control zone. At Class G airfields (like Gloucestershire, Blackpool and Exeter) an ATZ exists but there is no control zone — pilots must still follow the rules of the zone but need no clearance to enter it.
- AFFIRMRadio
- Yes. The standard word — never 'yeah'.
- Airspace classAirspace
- UK airspace is divided into classes A to G, each with different rules for who may enter and whether air traffic control must separate them.Class D is controlled airspace where aircraft need a clearance to enter and the controller provides separation. Class G is uncontrolled airspace — the most common around small airfields — where no clearance is needed to enter and pilots are responsible for seeing and avoiding other traffic.
- AltimeterAltitude
- A barometer calibrated to show height or altitude, depending on the pressure set.
- Approach controlAirfield
- Control of arriving and departing traffic in the airfield's wider airspace.
- ApronAirfield
- The parking area where aircraft load, unload and shut down.
- Area controlAirfield
- Control of en-route traffic at higher levels, handed between sectors.
- BacktrackAirfield
- Taxiing along the runway against the direction of use, to reach the start of it.
- BaseTraffic
- The descending turn back towards the runway, between downwind and final.
- CallsignRadio
- The name identifying an aircraft on frequency: a registration or an airline designator plus flight number.
- CAP 413Rules
- The UK CAA radiotelephony manual: what to say on the radio, and in what order.Official document ↗
- CircuitTraffic
- The rectangular pattern flown around the runway: upwind, crosswind, downwind, base, final.
- Circuit heightAltitude
- The height flown in the visual circuit, commonly 1000 ft above the aerodrome.
- ClearanceRules
- Permission to do one specific thing, in a specific place, at a specific time.
- Cleared for take-offTraffic
- Permission to depart from the named runway. Always read back in full.
- Cleared to landTraffic
- Permission for that aircraft to land on the named runway.
- Control areaAirspace
- A layer of controlled airspace above or around a control zone, starting at a set altitude rather than the surface.Together a control zone (from the surface) and a control area (the layer above) make up the controlled airspace around a major airport.
- Control zoneAirspace
- A volume of controlled airspace around an aerodrome, from the surface up to a set height.Aircraft need a clearance from the controller to enter a control zone. Class D control zones surround airports like Newcastle, Stansted and Manchester.
- CrosswindTraffic
- The first circuit turn, at right angles to the runway.
- DownwindTraffic
- The circuit leg parallel to the runway, flown in the opposite direction at circuit height.
- FinalTraffic
- Lined up with the runway on the approach to land.
- Flight levelAltitude
- Altitude in hundreds of feet on the standard 1013 hPa setting. FL80 is 8000 ft.
- FrequencyRadio
- The radio channel a controller works on, given in megahertz, e.g. 124.6.
- Frequency changeAirspace
- An instruction telling a pilot to switch to the next controller's frequency after leaving your airspace.Once a departing aircraft is clear of the circuit, the tower hands it to approach, radar, or an information service.
- Go aroundTraffic
- Abandon the approach, climb away and rejoin. Always the safe answer when in doubt.
- HelimedTraffic
- Callsign prefix used by UK air ambulance helicopters.
- Holding pointAirfield
- A marked position short of the runway where an aircraft waits for clearance.
- IFRAirspace
- Flight by reference to instruments, typically in cloud or poor visibility. ATC provides separation.Airliners almost always fly IFR. Instrument approaches and departures are flown under IFR.
- ILSAirspace
- A ground-based system that guides an aircraft onto the runway centreline and descent path using radio beams.ILS approaches are used at Blackpool (runway 28) and Exeter (runway 26), among others.
- Instrument approachAirspace
- A published procedure flown by reference to instruments to position an aircraft for landing, often in cloud.Airliners at Stansted and Manchester fly instrument approaches — there is no visual circuit at either field.
- Joining instructionsTraffic
- How an arriving aircraft is to enter the circuit, with runway and QNH.
- KnotsTraffic
- Nautical miles per hour — the unit for wind and aircraft speed.
- Line up and waitTraffic
- Take position on the runway and hold. This is not a take-off clearance.
- NEGATIVERadio
- No, or permission not granted, or that is not correct.
- Noise preferential routeAirspace
- A published route departing aircraft are expected to follow to keep noise away from built-up areas.Used at Manchester and Stansted to limit overflight of towns and cities on climb-out.
- OrbitTraffic
- Fly a complete circle where you are, to buy the controller time.
- Overhead joinAirspace
- A way of joining the circuit by arriving over the airfield at height, then descending on the dead side into the circuit pattern.The standard joining method at many UK GA airfields so arriving aircraft can see the runway in use and existing traffic.
- Phonetic alphabetRadio
- Alpha, Bravo, Charlie… — spoken letters that survive a poor radio signal.
- QFEAltitude
- Pressure setting that makes the altimeter read height above the aerodrome.On the runway the altimeter reads zero. Still used for circuit flying at some UK airfields.
- QNHAltitude
- Pressure setting that makes the altimeter read altitude above mean sea level.Passed with joining and taxi instructions and always read back, so every aircraft in the circuit shares the same vertical picture.
- Radar serviceAirspace
- A service where a radar controller helps a pilot by providing traffic information or separation.At Class G airfields like Blackpool and Exeter a radar service may be available even though there is no control zone.
- READ BACKRadio
- Repeat my message back so I can confirm you received it correctly.Mandatory for runway clearances, levels, headings, pressure settings and transponder codes.
- RegistrationRadio
- An aircraft's permanent identity marks. UK aircraft begin with G, e.g. G-BKTM.
- Reporting pointAirspace
- A named visual position where pilots report their position to the controller — a town, a mast, a junction.Visual Reporting Points (VRPs) help the controller build a picture of where VFR traffic is when there is no radar separation.
- ROGERRadio
- I have received your last transmission. Not agreement, and not a promise to comply.
- Rules of the AirRules
- The UK regulations governing how aircraft must be flown and who gives way to whom.
- RunwayAirfield
- The strip used for take-off and landing, numbered by its magnetic direction.A runway pointing 272° is runway 27; used the other way it is runway 09.
- Runway alternationAirspace
- A system at busy airports that spreads noise by switching between runways at set times.Manchester alternates between its two parallel runways to share noise fairly across the surrounding area.
- Runway incursionAirfield
- An aircraft or vehicle on the runway when it should not be — a serious safety event.
- SAY AGAINRadio
- Repeat your last message, or the part of it I have named.
- SeparationRules
- The minimum distance or time kept between aircraft so they cannot conflict.
- Special VFRAirspace
- A clearance allowing a VFR flight to enter a control zone in conditions below normal VFR weather minima.The controller accepts responsibility for separation from other SVFR and IFR traffic inside the zone.
- Standard pressureAltitude
- 1013 hPa, set above the transition altitude so aircraft are separated by flight levels.
- STANDBYRadio
- Wait, I will call you. Neither a clearance nor a refusal.
- Surface windAirfield
- Wind at the aerodrome, passed as direction in degrees and speed in knots.
- TaxiwayAirfield
- The marked paths aircraft use to move between the apron and the runway.
- Telephony designatorRadio
- The spoken company name in an airline callsign — 'Speedbird' for British Airways.
- Traffic informationTraffic
- Details of other aircraft passed to a pilot, without an instruction attached.
- Transition altitudeAltitude
- The altitude at which aircraft change from QNH to standard pressure when climbing.
- Transponder codeTraffic
- The four-digit code an aircraft sets so radar can identify it. Read back in full.
- UK AIPRules
- Aeronautical Information Publication — the official details of every UK aerodrome and airspace.
- UpwindTraffic
- Climbing straight ahead after take-off, along the runway direction.
- VFRAirspace
- Flight by visual reference to the ground and horizon, outside cloud. The pilot sees and avoids other traffic.VFR aircraft in a control zone need a clearance to enter. In Class G they can enter freely but must still follow the rules of the air.
- WILCORadio
- I understand your message and I will comply with it.
- Zone transitAirspace
- A clearance for a VFR aircraft to pass through a control zone from one side to the other.The controller may refuse, allow direct, or route the aircraft around the approach path. At Newcastle and Stansted, zone transits are common.